Self-priming pump



June 11, 1963 H. M. POLLAK SELF-PRIMING PUMP Filed July 28, 1960INVENTOR HEN/P) M. P0 LAK 3,093,085 SELF-PRIMHNG PUMP Henry M. Pollalt,Easton, Pa., assignor to Ingersoll-Rand Company, New York, N.Y., acorporation of New Jerse y Filed July 28, 1960, Ser. No. 46,606

6 Claims. (Cl. 103--113) This invention relates to self-primingcentrifugal pumps.

The invention is an improvement and modification of a pump of the typedescribed in co-pending application, Serial No. 31,378, filed May 24,1960, by Alexander Brkich and assigned to the same assignee as thepresent application, now U.S. Patent No. 3,082,694, dated March 26,1963, and differs therefrom in at least one respect in that thedischarge of the priming pump does not pass into the discharge line ofthe main pumping element. In accordance with this invention, gas isevacuated from a liquid head to a centrifugal pump and discharged toatmosphere by a priming pump to completely discharge such air from asystem, whereupon the priming element substantially ceases to provide anoutput.

It is accordingly an object of this invention to provide such anarrangement having means to effectively evacuate the liquid head to amain pump of accumulated air to permit effective pumping of liquid bythe main pump.

Another object of this invention is to provide the aforementionedarrangement wherein part of the main pump discharge is transmittedthrough the priming element to the main pump inlet in a directionopposite to normal flow, when the priming element is pumping, to providealong such flow path a cooling and regenerative flow.

This invention contemplates a self-priming pump comprising a centrifugalrotor disposed in a housing having a rotor inlet and discharge. Apriming pump is disposed in the housing and has an inlet connected tothe rotor in- 'let, and a discharge normally communicating withatmosphere through a valve. The valve is connected to the rotordischarge and is responsive to pressure thereat for closing suchcommunication to atmosphere and for connecting the two discharges foreffecting reverse flow through the priming pump to the rotor inlet.

The invention will be more completely understood, as will other objectsand the advantages of the invention, by reference to the followingdescription of a preferred embodiment shown in the drawing, in which thesingle FIG- URE shows in longitudinal section parts of a centrifugalpump and its priming element and the valve by which the evacuated air isdischarged to atmosphere.

Referring to the drawing, it will be noted that the centrifugal pump andpriming elements thereof are substantially identical with those of theabove mentioned copending application wherein a centrifugal main pumprotor 12 is disposed in a casing or housing having a rotor inlet portionor nozzle 14 leading to the eye of rotor 12 and a rotor dischargepassage 16. Housing 10 has a hollow cylindrical extension 18 disposedlongitudinally therefrom to house a water ring type pump having a casing26 and rotor 22 for priming the main pump rotor. For priming the system,air is evacuated from an inlet passage 24 within inlet nozzle 14 by asuitable inlet passage 26, diagrammatically indicated, connected to aninlet cavity 28 within extension 18 of casing 10. Rotation of thepriming pump 22 causes discharge of air into a discharge passage 30having a discharge pipe 32 leading to a valve 34.

As has been said above, the pump, as regards centrifugal and primingparts, is identical with those parts as shown and described in theaforementioned co-pending patent application, and for convenience theforegoing is abridged.

Patented June 11, 1963 Valve 34 consists of a hollow tubular bodyportion 36, very similar to a pipe T fitting. Two ends of body 36 arefitted with plugs 38 and 40, while a side aperture 42 and pipe 32 arethreadedly connected. Plug 38 has a threaded aperture 44 to receive asuitable lead-off pipe 46. The inner end of aperture 44 forms a portseat 48 adapted to 'be closed by the end of a reciprocal element 50which may be cylindrical, as shown. Element 50 is also adapted tocooperate with another seat port 52 in plug 40 at the inner end of anaperture 54 threaded to receive a pipe 56 leading to discharge passage16. Reciprocal element 50 is guided within a sleeve 58 which fitselement 50 very loosely. Normally element 50 is held on its seat 52 by aspring 6!) fitting about a reduced end portion 62 of element 5t).

Discharge passage or nozzle 16 is connected to a discharge line 64, andnozzle 16 is preferably provided with a check valve 66 of any suitableand well known construction for sealing the discharge system of the unitso a vacuum is created in the system during the priming cycle to primethe centrifugal impeller 12.

In operation, starting the apparatus by rotation of rotor 12 and thepriming pump rotor 22 starts evacuation of air from inlet passage 24,via conduit 26 and discharge passage 32, into the interior of valve body34, and thence out through pipe 46 to atmosphere or to any convenientplace of disposal. Pump rotor 12 is very ineffective at pumping gaseousfluid or air and, therefore, until substantially all the air isevacuated from the system or until at least enough air to submerge rotor12 has been removed, a vacuum of appreciable value will exist indischarge 16 and in pipe 56. However, as soon as rotor 12 begins tooperate on liquid instead of air, pressure will develop in dischargepassage 16 and pipe 56' and exerts a pressure against pressure face 68on the end of element 5t} and in opposition to the force of spring 60 tourge element 50 to close seat port 48. This closure concludes thepriming or effective pumping action of the Water ring pump, as rotor 22is not adapted to develop pressures of any considerable range.

However, rotor 22 will normally continue to churn liquid. Withoutcirculation of liquid the rotor would become heated and consequentlytroublesome. This heating is prevented by the introduction of liquid ina reverse direction through discharge pipe 32 by Way of the passageafforded between element 50 and sleeve 58. Such liquid can find its waythrough the priming pump past and in opposition to the rotor 22, and byway of passage 26 to the inlet passage 24.

It will be understood that the elements, rotors 12 and 22, may be drivenby an suitable means, in this instance, a motor 70 suitably supported oncasing 10 by a frame 72.

Thus, by the above construction are accomplished, among others, theobjects hereinbefore referred to.

I claim:

1. A self-priming centrifugal pump comprising a housing for a rotor anda priming ump and having rotor inlet and discharge passages, acentrifugal rotor disposed in said housing, a priming pump disposed insaid housing having an inlet connected to the rotor inlet and adischarge passage, and a valve connected to the priming pump dischargepassage normally open to pass fluid from the priming pump to atmosphere,said valve having a pressure face connected to the rotor dischargepassage to effect closing of said valve to atmosphere upon developmentof pressure in the rotor discharge passage and to connect the rotordischarge passage to the priming pump discharge passage.

2. A self-priming centrifugal pump comprising a housing for a rotor anda priming pump and having rotor inlet and discharge passages, acentrifugal rotor disposed in said housing, a priming pump disposed insaid housing having an inlet connected to the rotor inlet and adischarge passage, and a valve connected to the priming pump dischargepassage normally open to pass fluid from the priming pump to atmosphere,said valve having a pressure face connected to the rotor dischargepassage to effect closing of said valve to atmosphere upon developmentof pressure in said rotor discharge passage, said valve providing apassage connecting the rotor and priming pump discharge passages to eachother when said valve is closed to atmosphere and being controlled bysaid pressure face.

3. A self-priming centrifugal pump comprising a housing for a rotor anda priming pump and having rotor inlet and discharge passages, acentrifugal rotor disposed in said housing, a priming pump disposed insaid housing having an inlet connected to the rotor inlet and adischarge passage, a valve having a hollow body portion connected to therotor discharge passage by a seat port and having another seat portcommunicating with atmosphere, said valve being connected to the primingpump discharge passage, and a reciprocating element in said valvecooperating with said seat ports to connect said priming pump dischargepassage alternatively to said ports.

4. A self-priming centrifugal pump comprising a housin g for a rotor anda priming pump and having rotor inlet and discharge passages, acentrifugal rotor disposed in said housing, a priming pump disposed insaid housing having an inlet connected to the rotor inlet and adischarge passage, a valve having a hollow body portion connected to therotor discharge passage by a seat port and having a second seat portcommunicating with atmosphere, said valve being connected to the primingpump discharge passage, and a reciprocating element in said valvecooperating with said seat ports to connect said priming pump dischargepassage alternatively to said ports, said element having a pressure faceassociated with said rotor discharge passage closing the first seat portduring priming and being responsive to the rotor output to eifect suchreciprocations.

5. A self-priming centrifugal pump comprising a housing for a rotor anda priming pump and having rotor inlet and discharge passages, acentrifugal rotor disposed in said housing, a priming pump disposed insaid housing having an inlet connected to the rotor inlet and adischarge passage, a valve having a hollow body portion connected to thepriming pump discharge passage, said valve having a seat port connectedto the rotor discharge passage and another seat port communicating withatmosphere, a reciprocating element in said valve cooperating with saidseat ponts to connect said priming pump discharge passage alternativelyto said seat ports, and a sleeve fixed in said valve and disposed aboutsaid reciprocating element to form a restricted passage from said rotordischarge passage seat port to the interior of said hollow valve bodyportion.

6. A self-priming centrifugal pump comprising a housing for a primingpump and a pump rotor and having rotor inlet and discharge passages, arotor disposed in said housing, a priming pump disposed in said housinghaving an inlet connected to the rotor inlet and a discharge passage,I8, valve having a hollow body portion connected to the priming pumpdischarge passage and having a pair of seat ports one being connected tothe rotor discharge and the other communicating with atmosphere, areciprocating element in said hollow body portion cooperating with saidseat ports to connect said priming pump discharge passage alternativelyto atmosphere and the rotor discharge passage, a sleeve fixed in saidvalve and disposed about said reciprocating element to form 'arestricted passage from said rotor discharge passage seat port to theinterior of said hollow body portion, and a spring normally holding saidreciprocating element on said rotor discharge passage seat port.

References Cited in the file of this patent UNITED STATES PATENTS2,149,454 McBath Mar. 7, 1939 FOREIGN PATENTS 304,905 Great Britain Jan.31, 1929 319,176 Germany Mar. 1, 1920 361,480 Germany Oct. 14, 1922430,421 Italy Feb. 13, 1948 462,232 Germany July 6, 1928 462,233 GermanyJuly 6, 1928

1. A SELF-PRIMING CENTRIFUGAL PUMP COMPRISING A HOUSING FOR A ROTOR ANDA PRIMING PUMP AND HAVING ROTOR INLET AND DISCHARGE PASSAGES, ACENTRIFUGAL ROTOR DISPOSED IN SAID HOUSING, A PRIMING PUMP DISPOSED INSAID HOUSING HAVING AN INLET CONNECTED TO THE ROTOR INLET AND ADISCHARGE PASSAGE, AND A VALVE CONNECTED TO THE PRIMING PUMP DISCHARGEPASSAGE NORMALLY OPEN TO PASS FLUID FROM THE PRIMING PUMP TO ATMOSPHERE,SAID VALVE HAVING A PRESSURE FACE CONNECTED TO THE ROTOR DISCHARGEPASSAGE TO EFFECT CLOSING OF SAID VALVE TO ATMOSPHERE UPON DEVELOPMENTOF PRESSURE IN TEH ROTOR DISCHARGE PASSAGE AND TO CONNECT THE ROTORDISCHARGE PASSAGE TO THE PRIMING PUMP DISCHARGE PASSAGE.